Don't stop and restart GCM when extension/app is being updated

chrome/browser/extensions/extension_gcm_app_handler.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_GCM_APP_HANDLER_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_GCM_APP_HANDLER_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 38 matching lines @@
   virtual void ShutdownHandler() OVERRIDE;
   virtual void OnMessage(
       const std::string& app_id,
       const gcm::GCMClient::IncomingMessage& message) OVERRIDE;
   virtual void OnMessagesDeleted(const std::string& app_id) OVERRIDE;
   virtual void OnSendError(
       const std::string& app_id,
       const gcm::GCMClient::SendErrorDetails& send_error_details) OVERRIDE;
 
  protected:
+  // Could be overridden by testing purpose.
   virtual void OnUnregisterCompleted(const std::string& app_id,
                                      gcm::GCMClient::Result result);
+  virtual void AddAppHandler(const std::string& app_id);
+  virtual void RemoveAppHandler(const std::string& app_id);
 
- private:
+  gcm::GCMDriver* GetGCMDriver() const;
+
+private:
   friend class BrowserContextKeyedAPIFactory<ExtensionGCMAppHandler>;
 
   // ExtensionRegistryObserver implementation.
   virtual void OnExtensionLoaded(content::BrowserContext* browser_context,
                                  const Extension* extension) OVERRIDE;
   virtual void OnExtensionUnloaded(
       content::BrowserContext* browser_context,
       const Extension* extension,
       UnloadedExtensionInfo::Reason reason) OVERRIDE;
   virtual void OnExtensionUninstalled(content::BrowserContext* browser_context,
                                       const Extension* extension) OVERRIDE;
 
-  gcm::GCMDriver* GetGCMDriver() const;
+  void AddDummyAppHandler();
+  void RemoveDummyAppHandler();
 
   // BrowserContextKeyedAPI implementation.
   static const char* service_name() { return "ExtensionGCMAppHandler"; }
   static const bool kServiceIsNULLWhileTesting = true;
 
   Profile* profile_;
 
   // Listen to extension load, unloaded notifications.
   ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
       extension_registry_observer_;
 
 #if !defined(OS_ANDROID)
   scoped_ptr<extensions::GcmJsEventRouter> js_event_router_;
 #endif
 
   base::WeakPtrFactory<ExtensionGCMAppHandler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionGCMAppHandler);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_GCM_APP_HANDLER_H_